NO! Thiry Five years ago I moved into a more rural area. Every house had acreages. So me being a car guy was out in the garage working on something on a warm summer peaceful morning and I heard something fire up at this house probably 3/4 of a mile away. I walked out by the street to see what it was. Here comes this black 69 vette running it through the gears and on down the road past me. I was thinking Damn that thing is loud! I need to talk to him about it. Few hours later I could hear the Vette coming before I could even see it. So I walked out to the street and waved him down. 350 ci Lt1 with a Duntov 30/30 solid cam and the no baffles just 4 inch black turn out side pipes. I kind of ask him about using an antiquated grind like the 30/30, but anyway I showed him my 79 with it's modded 355, single plane and long tube headers. We hit it off and became friends over the years.

He told me that with the inserts in to quiet it down that it just ruined the performance. He also got some burns over the years and noise fix it tickets. I had a modded tranny and 3.55 rear he had 3.73 and a 4 speed. I always kicked his butt in drag races out in front of my house. It wasn't just the launch because I would walk away at 50 mph rolling starts.

They just aren't tuned header exhaust and the 30/30 cam no matter how we tried to dial it in just belonged in a history book. Years latter I helped install a solid roller.

 

Love my Hookers. I'm on my second set now after the first set from the 70's rusted out. I run the STS baffles and have modified them so I can uncork them at the track. So much easier to work under the car. Like you, I am running a 383/TKO-600 so the .64 OD tames the noise when hammering down the Interstate.

 

Mako,
How do you uncork them ? I was looking at doing this eventually. Uncapped they are very loud on the street.

 

I was one of STS's first customers. I did the mod years ago and I can't find any pictures anymore. The only pic I have is below. On the left of the STS baffle is a cap that they spot welded on. Basically you cut the cap's spot welds off which opens up the whole length of the tube.
I wanted to be able to have an insertable plug which I could remove and reinstall all from the exhaust end of the Hooker sidepipe while on the car. I machined a pipe fitting so it would fit inside the STS tube and drilled a hole down thru both the pipe and pipe fitting which I threaded for the drop down bolt. I can drop a threaded bolt from the top down thru the STS tube and pipe fitting locking it in with a wrench. I didn't want to have something that would vibrate loose while driving down the highway and hit a car behind. You'll have to figure it all out on how to do it. But it's doable, I can remove or reinsert the plug, tighten the bolt with a small wrench all the while reaching in thru the 4" Hooker exhaust opening. When I go to the track I can remove the plug and reinstall for the drive home. It's definitely much louder with the plug removed. There's probably many other ways ways to accomplish the same thing.

 

Like said above, there not anywhere near what is needed in primary length. Headman side pipe headers are much more closer to right. Around 28" I believe. I have some here in a box.

 

So the Hooker primaries are too LONG? This site seems to indicate that they are 46" long.

https://www.holley.com/products/disc.../parts/2234HKR

Sure, you could do better under the car with an X-pipe, and If I had an LS or were otherwise starting from scratch, I'd absolutely do that. But c'mon!

 

Yes, there way to long.

 

After consideration and owners thoughts, I am staying w/ my Flowmaster 40’s and X-pipe to eliminate exhaust back flow.

Sound is a nice Rumble,Lope.

 

Here is Pipemax sim recommendedexhaust for a 350.Pipemax is empirical. Been proven many times to work well on exhaust design .

​​​​​​​ I use its recommended exhaust lengths,diameters in eng mod 4t sim. It completely agrees as well.or watch engine masters. Typical 30 inch header works well with 18" collectors. Why do most manufacturers make them so long. ​​​​​​​idk. They don't want make new building fixtures is my 1st guess.

 

That's why the Stahls perform so well. I believe their primaries are 28 inches long and do not make that bend around the corner. Bottom line is dont do the Hookers for a performance upgrade. Do it because you like the look and dont care about your hearing lol.😂

 

There is some interesting internet reading to do when you search for Pipemax.

I'm guessing that the #1 reason for the length of the Hooker-style side pipe headers is for clearance under the frame. 4x1.75" pipes crossing side by side have double the ground clearance of a single 4" pipe. The Stahl headers (now made/sold via ACP Headers) imply a solution, but don't show it in pictures.

https://acpheaders.com/sb-drag-race-...t-headers.html

 

Nearly every GM C3 racecar had them and they made great power.

Years ago someone here dynoed open headers vs STS inserts uncapped and the horsepower loss was less than 15hp. I ran mine with no muffler and with the STS baffles uncapped and and it was MUCH more quiet without any noticeable power loss.

My BB with uncapped STS inserts.

 

I don't think the bend is near as bad as the lengths,collectors in completely wrong spot.
Scavenging not near ideal.
you can get creative where there is bend. .

 

Is exhaust smell ever a problem? The exhaust exit is near driver parallel. The only real advantage that I see are looks, (& they do Look Good). Sidepipes do look Much better on chrome bumper C-3’s.

 

[QUOTE=Corey_68;1606261719]Nearly every GM C3 racecar had them and they made great power.

Either they re engineered them or they didn't make great power. You can't change the facts.

 

GM did not use Hooker side mount headers on their race cars. I was speaking to the point in the original post of side mount headers are "not great performance enhancers". GM contracted OK Kustom to build the side mount headers for the L88 racing program and were available through dealerships. The '68 L88 of Heinz and Johnson made 660hp running these side mount headers, not bad I must say.

 

Except the race cars didn't need to run mufflers. Those are the killers of power with these side exhaust systems. The last muffler I used in my Hookers was a spliced in Dynomax 3 inch, 18 inch long race bullet in each tube. It was down 6 horsepower from open tubes. Lost over 20ftlb in the midrange however. Next best were STS uncapped and shortened baffles. These were tested on a 605hp big block. The problem was, these two configurations were way too loud for me to enjoy driving the car, and I do realize that is subjective. The Hooker reverse flows and glass pack mufflers lost 120 and 75hp, when the motor was in 440hp form. In fact, the first test I did with the reverse flows, I blew a sidetube off, I guess from all the back pressure lol. I definitely would run the STS baffles if I still had them. They probably wouldn't lose much up to 400hp and sound great. I just want to keep all my power and not make a ton of noise. Call me old lol!

Bill

 

How was the noise level with the reverse flow mufflers Bill? Thanks.

 

The reverse flow mufflers were very quiet.

 

I love the look of the side pipes on the C3 - either from the Hooker design or the original OEM design. To me, the look overrides the function (and potential hearing loss). Seeing a C3 without side exhaust is like seeing a Shelby Cobra without side exhaust! (Exaggeration)
My experience has been interesting over the years. I first put the side pipes on my car in the mid 90s and they've been on ever since. My general rule of thumb: stay above 2.5" straight through in the side pipe if you can. Preferably 3" - 4" if you can get away with it. I've run the following configurations:

1. Reverse flow mufflers: Quiet, but will absolutely crush any exhaust flow.
2. No muffler: Minimal loss in flow, but you will go deaf - and your neighbors will hate you. That configuration lasted about one afternoon.
3. Glasspack inserts: These have an acceptable noise level and sound, but I didn't love that they squeezed the flow path down to about 2.25" or 2.5" (can't remember exactly). I ran these for a handful of years.
4. Custom auger style inserts: I played with this, installing some, then removing, etc... I couldn't get the sound right, and it was generally too loud as you tried to go with less of the inserts.
5. STS Baffles with caps: These were a really good solution. The sound was good, and the sound level was acceptable. However, there will be a flow restriction with the caps, and I don't think there is any internet dyno data with capped STS baffles. There's probably a marketing reason for that.
6. STS Baffles without caps: This was a tad too loud for me. Although the internet dyno numbers for the uncapped STS baffles show minimal HP loss, you'll probably get more than minimal hearing loss with completely uncapped baffles. The other option (which I didn't try) was drilling a hole in the cap to sort of "tune" the sound level to taste. Perhaps others have tried this and can comment.
7. Custom built side pipe with 3.5" Borla racing mufflers: I loved this concept, and I'm sure the flow was about as good as it gets, but too loud. I needed ear plugs to drive pretty much anywhere. If I could figure out how to make this design quieter, I'd go with it. If Borla made a 30" long version of the muffler I used, it might help attenuate more sound, but I had to abandon that design.
8. Custom built side pipe with flowmaster 3" tandem mufflers: I tried welding two mufflers in series for this design. In the end, I had the 3" straight through, but just a tad too loud.
9. Classic Chambered Exhaust Louver Core Inserts: These are my current side pipe muffler inserts. I've had them installed for about a month or so. They have a 3" diameter pass through core using a louver design and a sound deadening material (fiberglass) that uses the outer "side pipe" as the outer shell. They are relatively light, use the entire pipe, and have a decent sound reduction / decent sound. You can get them in either 3" or 2.5" cores (passthrough). http://www.classicchambered.com/clas...html#corvettes

I've sort of learned that side pipes are a very subjective thing, and are a mixture of cosmetic tastes, and minimal performance loss (at least for me). If you like the looks, but don't care about the performance loss, go with the reverse flow inserts. If you like the looks and don't want to minimize any performance loss, you can't beat the straight pipes - your ears will bleed, and your neighbors will be chasing you with pitchforks through the countryside... When you are trying to optimize both for the looks and performance, that's where it gets tricky. In that case, I would advise going with either the STS baffles, or the Classic Chambered Exhaust products.

KT